横向静载作用下轨道交通预应力混凝土U型梁裂缝开展研究OA

In order to study the crack development of prestressed concrete U-shaped beam structure of rail transit under plate transverse stress,the causes were reviewed and summarized.Taken a standard beam section of a practi-cal project as an example,the transverse static load failure test was carried out to analyze the variation law of strain and deflection,the crack development and the structural damage of prestressed concrete U-shaped beam structure under transverse loading.The result shows that the U-shaped beam shows good overall performance and lateral cracking resistance with the increase of loading stage under transverse symmetric load;The crack damage occurs firstly at the plate and the bottom,and then gradually develops to the joint of the bottom and the plate;Under the failure loading stage,destructive crack damage and obvious outward expansion deformation occur at the plate and flange;Within the range of lateral static load which is 2 times higher than the recommended value of the impact force of the code,the test beam can maintain the elastic working state,which verifies the rationality of the recom-mended value of train derailment impact force in American ACI code to design the transverse collision resistance of U-shaped beam.The research results can provide more references for the mechanical properties research and struc-tural optimization design of prestressed concrete U-shaped beams of rail transit.